Baseball's First-Half Surprises

The 2014 Major League Baseball season has officially passed its midpoint. To open Sunday's slate, the White Sox shut out the Blue Jays in the 1,215th game of 2,430 on the schedule. With half the season remaining, the statistical leaderboards feature a bevy of unfamiliar faces at the top. How are these first-half surprises doing it, and can they hold up?

Hitters

Scooter Gennett: Leads MLB second basemen with .837 OPS*

At 5-foot-10 and 170 pounds, Ryan "Scooter" Gennett was not expected to hit for power. The lazy comparison for Gennett was former Brewers keystone man Jim "Gumby" Gantner, another scrawny scrapper who managed double-digit home runs just once over a 17-year career in Milwaukee. But Gennett has six home runs and 28 extra-base hits in 74 games and has the National League's best slugging percentage from a second baseman at .485 (only Ian Kinsler's .489 beats him from the American League). Gennett has made some use out of Miller Park's cozy right field, but this June 25 grand slam off Stephen Strasburg showed he can hit a no-doubter as well:

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Gennett's season is part of the larger success of Milwaukee's second base platoon. Between Gennett and right-handed mate Rickie Weeks, Brewers second basemen have produced an .822 OPS, best in the National League and 18 points ahead of Chase Utley's Phillies. Expect the platoon to stick, as Gennett has been useless in 75 career plate appearances against lefties (.324 OPS). Limited to starting against right-handed pitchers, Gennett should continue to rake -- his .311/.351/.485 in 266 plate appearances thus far is a near carbon copy of his .324/.356/.479 mark in 230 plate appearances in 2013, which puts his run of excellent performance at practically a whole season now.

Seth Smith: Leads National League left fielders with .883 OPS

Left field in the National League is home to former All-Star sluggers Matt Holliday, Justin Upton and Matt Kemp, but none have managed the pace of perennial platoon stud Smith thus far. Smith is doing it with excellent plate discipline -- 36 walks against just 44 strikeouts -- and hitting for power rarely seen from a lefty in San Diego. Some of that can be attributed to the shortened dimensions implemented last season, but the fact remains that Smith is on pace to become just the fourth left-handed batter to slug at least .450 in Petco Park's 11-year history -- Adrian Gonzalez did it from 2006-2010, Brian Giles did it in 2004, 2005 and 2008, and Will Venable was the only one to do it with the new layout last season.

The Padres are a dumpster fire offensively and carry a .605 OPS at the halfway point despite Smith's brilliance. Smith is a free agent after the season and as such seems like a good bet to be shuffled off by the trading deadline. Smart money should be on Upton, Holliday, Kemp or one of the National League's bigger names in left field outhitting him over the rest of the season, but Smith has been an above-average hitter for four years running. He can be an upgrade for nearly any team in contention, particularly against right-handed pitching (.289/.384/.515 in 238 plate appearances this year, .280/.361/.490 career).

Casey McGehee: Leads National League third basemen with 48 RBIs

In 1912, Bill Sweeney hit one home run in 699 plate appearances for the Boston Braves. Fortunately, Sweeney had 203 other hits, and he finished the season with a brilliant .344/.416/.445 batting line and knocked in a cool 100 runs. In the 102 years since, according to the Baseball-Reference Play-Index, nobody else has touched 100 RBIs without hitting at least two home runs, and just 10 players have reached 80 without hitting home runs, plural, the latest being Pie Traynor in 1933. Yes, Pie.

McGehee has just one home run for Miami in 2014, his first year back in the majors after he spent 2013 as Masahiro Tanaka's teammate on the NBP champion Rakuten team. McGehee has made up for it with a career high 10 percent walk rate, a career low 14.9 percent strikeout rate and 19 doubles. He is hitting behind Giancarlo Stanton in the Marlins' lineup and has already knocked Stanton in 16 times. Stanton has been intentionally walked 15 times already, and even though McGehee has shown he can knock a single with the best of them this year, he has 20 fewer home runs than Stanton and will be challenged with runners on base as long as he occupies that lineup spot.

Expect McGehee to sock another home run at some point this year -- he hit 28 for Rakuten last year and his MLB career high is a robust 23 for Milwaukee in 2010. But right now, he's thriving on Marlins Park's huge outfield, and he's enjoying the most productive one-homer season we've seen since the dead ball era.

Pitchers

Johnny Cueto: Leads MLB starting pitchers with 1.88 ERA

Cueto has always had a special knack for pitching in Great American Ballpark. In 2011, he became the first Reds pitcher to throw over 100 innings with an ERA under 3.00 since the aptly-nicknamed Smallpark went up in 2003. If not for a shoulder injury in 2013, Cueto would be on his way to doing it for the fourth straight year. But with the shoulder injury -- Cueto made just 11 starts in 2013 and missed roughly 10 starts to a similar injury in 2011 -- he was off the radar compared to big talents like Clayton Kershaw, Adam Wainwright, Madison Bumgarner and other aces who not only have comparable talent but get to practice their craft in larger, friendlier ballparks.

The money pitch for Cueto has always been his sinker. At 94 mph, it bores into opposing bats, and it's also his most reliable pitch for a strike, with a 68 percent strike rate. According to Brooks Baseball, Cueto has fired 412 sinkers this year and issued just 12 hits, including eight singles and zero home runs. As a pitcher working in a park that runs 328 and 325 feet down the lines and no deeper than 404 feet to center field, the reliable ground ball pitch is a necessity, and Cueto has worked his better than anyone thus far.

Sean Doolittle: Leads all MLB pitchers with 56.0 K/BB

In 2008, 21-year-old first baseman Sean Doolittle hit .305/.385/.560 with 18 home runs in 86 games in high Single-A ball. The 2009 Baseball Prospectus annual called him a "Gold Glove-caliber first baseman with the ability to hit for average." Naturally, five years later, here we are, and Doolittle has moved into the Athletics' closer role, saved 11 games, and struck out 56 against one measly walk in 39 innings. Second place in K/BB, minimum 20 innings, by the way, is Clayton Kershaw at 10.44.

Knee surgery wrecked Doolittle's career as a hitter, but he needed just 26 innings in the minors -- with an absurd 50 strikeouts against eight walks -- to reach the majors as a flame-throwing left-handed reliever. Control has been a strong point for Doolittle since his arrival, but he has taken it to another level in 2014, going 3-0 on just one of 141 opposing batters and 2-0 just 11 times. Doolittle is almost entirely a fastball pitcher -- 468 of his 549 pitches have been four-seam fastballs. No reliever draws more swings on their fastball than Doolittle (59 percent) and only Brad Boxberger, Aroldis Chapman and Wade Davis draw more whiffs per swing than Doolittle's 32.5 percent, making Doolittle's fastball arguably the most effective pitch in the league.

There's still plenty of baseball left, but halfway through the season, the picture is starting to clear up. These five players have all been huge for their teams in their own unique ways. The test will be if they can hold up over the upcoming dog days of summer.